- space, k for documentation on the thing under the cursor
- space, [yp] for copying/pasting to the system clipboard
- m, [ai], [acfo] for selecting around/in language structures
This is easy because Helix has a very fast command palette thing, and a lot of its commands are behind consistent prefixes, so if you know `mi(` for selecting within parentheses, you can do `mi` to ask "what other things can I select within?"
I'm not really in this camp though, I would prefer vim commands to somehow be more "discoverable".
Much easier said than done, though.